The idea of air conditioning began long before any system or machine was ever created. The concept of cooling air has been utilized as far back as Ancient Rome. The discovery that certain materials could be compressed to provide evaporative cooling led to centralized air conditioning systems. These systems improved with the creation of various fluorocarbon gases; however, in recent times the environmental impact of these gases has become a concern. For example, the refrigerants used in heating, ventilation, and air conditioning (HVAC) systems pose a serious threat to the ozone and our environment. The release of these refrigerants, which once were commonplace, is now a serious offense and controlled by law. It is extremely important that all refrigerant be removed or evacuated from HVAC systems that undergo major repair or subject to replacement. Many of these systems utilize an electrically-powered solenoid valve or check valve in the refrigerant loop.
Solenoid valves for controlling various fluid flow systems are used in many industrial and residential applications. They are used to control the flow of liquids or gases in a positive, fully-closed or fully-open mode. The solenoid valve is operated by opening and closing an orifice in a valve body that permits or prevents fluid flow. The orifice is opened or closed using a plunger that is raised or lowered within a sleeve tube by energizing a coil. In many systems the valve is normally closed, such that when the coil is energized, a magnetic field is produced, raising the plunger and allowing flow through the valve. Solenoid valves are also classified into two groups, those powered by an alternating current (AC) power source and those powered by a direct current (DC) power source.
Whether AC or DC powered, the solenoid is typically energized by the same power source which provides power to the overall system. In HVAC systems, under normal conditions without power applied, these valves are closed, thus isolating some of the refrigerant within the refrigerant loop. It is extremely difficult to access such refrigerant due to the lack of power which is not supplied to the unit during repair, replacement, or disposal.
Accordingly, there exists a need for a means by which solenoid valves in direct expansion air conditioning systems can be manually activated in a bypass manner to allow for complete removal of enclosed refrigerant. The development of the present invention substantially departs from the conventional solutions and in doing so fulfills this need.